1. Field of the Invention
The present invention relates to image processing, and, in particular, to encoding video signals.
2. Description of the Related Art
It is desirable to encode image data, such as motion video data, to reduce the number of bits used to represent the images for more efficient storage and/or transmission for subsequent playback. Conventional video encoders apply sophisticated encoding algorithms to achieve this video compression. These algorithms involve the control and selection of values to use for many different parameters involved in the encoding process. Typically, these parameters are controlled to achieve the highest quality output signal (e.g., the decoded video stream) for a specified target bit rate. The target bit rate specifies a goal for the average number of bits allocated for encoding each of the frames of the video sequence to be encoded. The video encoder adaptively and dynamically changes the values of different encoding parameters during the encoding processing to attempt to achieve the target bit rate. Other encoding parameters may be selected at the start of video encoding and left unchanged throughout a particular encoding session.
The present invention is directed to an improvement in such conventional parameter-driven video encoders that are designed to achieve a specified target bit rate.
Further objects and advantages of this invention will become apparent from the detailed description which follows.